492 lines
15 KiB
C
492 lines
15 KiB
C
![]() |
/* Driver for USB Mass Storage compliant devices
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* SCSI layer glue code
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*
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* $Id: scsiglue.c,v 1.26 2002/04/22 03:39:43 mdharm Exp $
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*
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* Current development and maintenance by:
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* (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
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*
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* Developed with the assistance of:
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* (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
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* (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
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*
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* Initial work by:
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* (c) 1999 Michael Gee (michael@linuxspecific.com)
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*
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* This driver is based on the 'USB Mass Storage Class' document. This
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* describes in detail the protocol used to communicate with such
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* devices. Clearly, the designers had SCSI and ATAPI commands in
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* mind when they created this document. The commands are all very
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* similar to commands in the SCSI-II and ATAPI specifications.
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*
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* It is important to note that in a number of cases this class
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* exhibits class-specific exemptions from the USB specification.
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* Notably the usage of NAK, STALL and ACK differs from the norm, in
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* that they are used to communicate wait, failed and OK on commands.
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*
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* Also, for certain devices, the interrupt endpoint is used to convey
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* status of a command.
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*
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* Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
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* information about this driver.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <scsi/scsi.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_devinfo.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_eh.h>
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#include "usb.h"
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#include "scsiglue.h"
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#include "debug.h"
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#include "transport.h"
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#include "protocol.h"
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/***********************************************************************
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* Host functions
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***********************************************************************/
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static const char* host_info(struct Scsi_Host *host)
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{
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return "SCSI emulation for USB Mass Storage devices";
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}
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static int slave_alloc (struct scsi_device *sdev)
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{
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/*
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* Set the INQUIRY transfer length to 36. We don't use any of
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* the extra data and many devices choke if asked for more or
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* less than 36 bytes.
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*/
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sdev->inquiry_len = 36;
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return 0;
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}
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static int slave_configure(struct scsi_device *sdev)
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{
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struct us_data *us = host_to_us(sdev->host);
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/* Scatter-gather buffers (all but the last) must have a length
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* divisible by the bulk maxpacket size. Otherwise a data packet
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* would end up being short, causing a premature end to the data
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* transfer. Since high-speed bulk pipes have a maxpacket size
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* of 512, we'll use that as the scsi device queue's DMA alignment
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* mask. Guaranteeing proper alignment of the first buffer will
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* have the desired effect because, except at the beginning and
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* the end, scatter-gather buffers follow page boundaries. */
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blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
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/* Set the SCSI level to at least 2. We'll leave it at 3 if that's
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* what is originally reported. We need this to avoid confusing
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* the SCSI layer with devices that report 0 or 1, but need 10-byte
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* commands (ala ATAPI devices behind certain bridges, or devices
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* which simply have broken INQUIRY data).
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*
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* NOTE: This means /dev/sg programs (ala cdrecord) will get the
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* actual information. This seems to be the preference for
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* programs like that.
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*
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* NOTE: This also means that /proc/scsi/scsi and sysfs may report
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* the actual value or the modified one, depending on where the
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* data comes from.
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*/
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if (sdev->scsi_level < SCSI_2)
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sdev->scsi_level = SCSI_2;
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/* According to the technical support people at Genesys Logic,
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* devices using their chips have problems transferring more than
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* 32 KB at a time. In practice people have found that 64 KB
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* works okay and that's what Windows does. But we'll be
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* conservative; people can always use the sysfs interface to
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* increase max_sectors. */
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if (le16_to_cpu(us->pusb_dev->descriptor.idVendor) == USB_VENDOR_ID_GENESYS &&
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sdev->request_queue->max_sectors > 64)
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blk_queue_max_sectors(sdev->request_queue, 64);
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/* We can't put these settings in slave_alloc() because that gets
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* called before the device type is known. Consequently these
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* settings can't be overridden via the scsi devinfo mechanism. */
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if (sdev->type == TYPE_DISK) {
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/* Disk-type devices use MODE SENSE(6) if the protocol
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* (SubClass) is Transparent SCSI, otherwise they use
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* MODE SENSE(10). */
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if (us->subclass != US_SC_SCSI)
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sdev->use_10_for_ms = 1;
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/* Many disks only accept MODE SENSE transfer lengths of
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* 192 bytes (that's what Windows uses). */
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sdev->use_192_bytes_for_3f = 1;
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/* Some devices don't like MODE SENSE with page=0x3f,
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* which is the command used for checking if a device
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* is write-protected. Now that we tell the sd driver
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* to do a 192-byte transfer with this command the
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* majority of devices work fine, but a few still can't
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* handle it. The sd driver will simply assume those
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* devices are write-enabled. */
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if (us->flags & US_FL_NO_WP_DETECT)
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sdev->skip_ms_page_3f = 1;
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/* A number of devices have problems with MODE SENSE for
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* page x08, so we will skip it. */
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sdev->skip_ms_page_8 = 1;
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/* Some disks return the total number of blocks in response
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* to READ CAPACITY rather than the highest block number.
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* If this device makes that mistake, tell the sd driver. */
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if (us->flags & US_FL_FIX_CAPACITY)
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sdev->fix_capacity = 1;
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} else {
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/* Non-disk-type devices don't need to blacklist any pages
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* or to force 192-byte transfer lengths for MODE SENSE.
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* But they do need to use MODE SENSE(10). */
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sdev->use_10_for_ms = 1;
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}
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/* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
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* REMOVAL command, so suppress those commands. */
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if (us->flags & US_FL_NOT_LOCKABLE)
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sdev->lockable = 0;
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/* this is to satisfy the compiler, tho I don't think the
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* return code is ever checked anywhere. */
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return 0;
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}
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/* queue a command */
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/* This is always called with scsi_lock(host) held */
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static int queuecommand(struct scsi_cmnd *srb,
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void (*done)(struct scsi_cmnd *))
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{
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struct us_data *us = host_to_us(srb->device->host);
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US_DEBUGP("%s called\n", __FUNCTION__);
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/* check for state-transition errors */
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if (us->srb != NULL) {
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printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
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__FUNCTION__, us->srb);
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return SCSI_MLQUEUE_HOST_BUSY;
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}
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/* fail the command if we are disconnecting */
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if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
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US_DEBUGP("Fail command during disconnect\n");
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srb->result = DID_NO_CONNECT << 16;
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done(srb);
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return 0;
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}
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/* enqueue the command and wake up the control thread */
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srb->scsi_done = done;
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us->srb = srb;
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up(&(us->sema));
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return 0;
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}
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/***********************************************************************
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* Error handling functions
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***********************************************************************/
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/* Command timeout and abort */
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/* This is always called with scsi_lock(host) held */
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static int command_abort(struct scsi_cmnd *srb)
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{
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struct us_data *us = host_to_us(srb->device->host);
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US_DEBUGP("%s called\n", __FUNCTION__);
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/* Is this command still active? */
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if (us->srb != srb) {
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US_DEBUGP ("-- nothing to abort\n");
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return FAILED;
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}
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/* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
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* a device reset isn't already in progress (to avoid interfering
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* with the reset). To prevent races with auto-reset, we must
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* stop any ongoing USB transfers while still holding the host
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* lock. */
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set_bit(US_FLIDX_TIMED_OUT, &us->flags);
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if (!test_bit(US_FLIDX_RESETTING, &us->flags)) {
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set_bit(US_FLIDX_ABORTING, &us->flags);
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usb_stor_stop_transport(us);
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}
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/* Wait for the aborted command to finish */
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wait_for_completion(&us->notify);
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/* Reacquire the lock and allow USB transfers to resume */
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clear_bit(US_FLIDX_ABORTING, &us->flags);
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clear_bit(US_FLIDX_TIMED_OUT, &us->flags);
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return SUCCESS;
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}
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/* This invokes the transport reset mechanism to reset the state of the
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* device */
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/* This is always called with scsi_lock(host) held */
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static int device_reset(struct scsi_cmnd *srb)
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{
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struct us_data *us = host_to_us(srb->device->host);
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int result;
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US_DEBUGP("%s called\n", __FUNCTION__);
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/* lock the device pointers and do the reset */
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down(&(us->dev_semaphore));
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if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
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result = FAILED;
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US_DEBUGP("No reset during disconnect\n");
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} else
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result = us->transport_reset(us);
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up(&(us->dev_semaphore));
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return result;
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}
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/* This resets the device's USB port. */
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/* It refuses to work if there's more than one interface in
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* the device, so that other users are not affected. */
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/* This is always called with scsi_lock(host) held */
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static int bus_reset(struct scsi_cmnd *srb)
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{
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struct us_data *us = host_to_us(srb->device->host);
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int result, rc;
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US_DEBUGP("%s called\n", __FUNCTION__);
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/* The USB subsystem doesn't handle synchronisation between
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* a device's several drivers. Therefore we reset only devices
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* with just one interface, which we of course own. */
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down(&(us->dev_semaphore));
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if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) {
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result = -EIO;
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US_DEBUGP("No reset during disconnect\n");
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} else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) {
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result = -EBUSY;
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US_DEBUGP("Refusing to reset a multi-interface device\n");
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} else {
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rc = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
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if (rc < 0) {
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US_DEBUGP("unable to lock device for reset: %d\n", rc);
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result = rc;
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} else {
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result = usb_reset_device(us->pusb_dev);
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if (rc)
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usb_unlock_device(us->pusb_dev);
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US_DEBUGP("usb_reset_device returns %d\n", result);
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}
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}
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up(&(us->dev_semaphore));
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/* lock the host for the return */
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return result < 0 ? FAILED : SUCCESS;
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}
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/* Report a driver-initiated device reset to the SCSI layer.
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* Calling this for a SCSI-initiated reset is unnecessary but harmless.
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* The caller must own the SCSI host lock. */
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void usb_stor_report_device_reset(struct us_data *us)
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{
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int i;
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struct Scsi_Host *host = us_to_host(us);
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scsi_report_device_reset(host, 0, 0);
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if (us->flags & US_FL_SCM_MULT_TARG) {
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for (i = 1; i < host->max_id; ++i)
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scsi_report_device_reset(host, 0, i);
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}
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}
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/***********************************************************************
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* /proc/scsi/ functions
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***********************************************************************/
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/* we use this macro to help us write into the buffer */
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#undef SPRINTF
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#define SPRINTF(args...) \
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do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
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static int proc_info (struct Scsi_Host *host, char *buffer,
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char **start, off_t offset, int length, int inout)
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{
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struct us_data *us = host_to_us(host);
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char *pos = buffer;
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const char *string;
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/* if someone is sending us data, just throw it away */
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if (inout)
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return length;
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/* print the controller name */
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SPRINTF(" Host scsi%d: usb-storage\n", host->host_no);
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/* print product, vendor, and serial number strings */
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if (us->pusb_dev->manufacturer)
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string = us->pusb_dev->manufacturer;
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else if (us->unusual_dev->vendorName)
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string = us->unusual_dev->vendorName;
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else
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string = "Unknown";
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SPRINTF(" Vendor: %s\n", string);
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if (us->pusb_dev->product)
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string = us->pusb_dev->product;
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else if (us->unusual_dev->productName)
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string = us->unusual_dev->productName;
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else
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string = "Unknown";
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SPRINTF(" Product: %s\n", string);
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if (us->pusb_dev->serial)
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string = us->pusb_dev->serial;
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else
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string = "None";
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SPRINTF("Serial Number: %s\n", string);
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/* show the protocol and transport */
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SPRINTF(" Protocol: %s\n", us->protocol_name);
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SPRINTF(" Transport: %s\n", us->transport_name);
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/* show the device flags */
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if (pos < buffer + length) {
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pos += sprintf(pos, " Quirks:");
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#define US_FLAG(name, value) \
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if (us->flags & value) pos += sprintf(pos, " " #name);
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US_DO_ALL_FLAGS
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#undef US_FLAG
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*(pos++) = '\n';
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}
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/*
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* Calculate start of next buffer, and return value.
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*/
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*start = buffer + offset;
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if ((pos - buffer) < offset)
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return (0);
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else if ((pos - buffer - offset) < length)
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return (pos - buffer - offset);
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else
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return (length);
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}
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/***********************************************************************
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* Sysfs interface
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***********************************************************************/
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/* Output routine for the sysfs max_sectors file */
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static ssize_t show_max_sectors(struct device *dev, char *buf)
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{
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struct scsi_device *sdev = to_scsi_device(dev);
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return sprintf(buf, "%u\n", sdev->request_queue->max_sectors);
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}
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/* Input routine for the sysfs max_sectors file */
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static ssize_t store_max_sectors(struct device *dev, const char *buf,
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size_t count)
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{
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struct scsi_device *sdev = to_scsi_device(dev);
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unsigned short ms;
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||
|
if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
|
||
|
blk_queue_max_sectors(sdev->request_queue, ms);
|
||
|
return strlen(buf);
|
||
|
}
|
||
|
return -EINVAL;
|
||
|
}
|
||
|
|
||
|
static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
|
||
|
store_max_sectors);
|
||
|
|
||
|
static struct device_attribute *sysfs_device_attr_list[] = {
|
||
|
&dev_attr_max_sectors,
|
||
|
NULL,
|
||
|
};
|
||
|
|
||
|
/*
|
||
|
* this defines our host template, with which we'll allocate hosts
|
||
|
*/
|
||
|
|
||
|
struct scsi_host_template usb_stor_host_template = {
|
||
|
/* basic userland interface stuff */
|
||
|
.name = "usb-storage",
|
||
|
.proc_name = "usb-storage",
|
||
|
.proc_info = proc_info,
|
||
|
.info = host_info,
|
||
|
|
||
|
/* command interface -- queued only */
|
||
|
.queuecommand = queuecommand,
|
||
|
|
||
|
/* error and abort handlers */
|
||
|
.eh_abort_handler = command_abort,
|
||
|
.eh_device_reset_handler = device_reset,
|
||
|
.eh_bus_reset_handler = bus_reset,
|
||
|
|
||
|
/* queue commands only, only one command per LUN */
|
||
|
.can_queue = 1,
|
||
|
.cmd_per_lun = 1,
|
||
|
|
||
|
/* unknown initiator id */
|
||
|
.this_id = -1,
|
||
|
|
||
|
.slave_alloc = slave_alloc,
|
||
|
.slave_configure = slave_configure,
|
||
|
|
||
|
/* lots of sg segments can be handled */
|
||
|
.sg_tablesize = SG_ALL,
|
||
|
|
||
|
/* limit the total size of a transfer to 120 KB */
|
||
|
.max_sectors = 240,
|
||
|
|
||
|
/* merge commands... this seems to help performance, but
|
||
|
* periodically someone should test to see which setting is more
|
||
|
* optimal.
|
||
|
*/
|
||
|
.use_clustering = 1,
|
||
|
|
||
|
/* emulated HBA */
|
||
|
.emulated = 1,
|
||
|
|
||
|
/* we do our own delay after a device or bus reset */
|
||
|
.skip_settle_delay = 1,
|
||
|
|
||
|
/* sysfs device attributes */
|
||
|
.sdev_attrs = sysfs_device_attr_list,
|
||
|
|
||
|
/* module management */
|
||
|
.module = THIS_MODULE
|
||
|
};
|
||
|
|
||
|
/* To Report "Illegal Request: Invalid Field in CDB */
|
||
|
unsigned char usb_stor_sense_invalidCDB[18] = {
|
||
|
[0] = 0x70, /* current error */
|
||
|
[2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
|
||
|
[7] = 0x0a, /* additional length */
|
||
|
[12] = 0x24 /* Invalid Field in CDB */
|
||
|
};
|
||
|
|